The 2025 edition of the BAMS State of the Climate report, published by the American Meteorological Society (AMS), shows several climate metrics reached new records last year, including atmospheric carbon dioxide concentration, glacial ice loss and global soil dryness.
Dr Robert Dunn of the Met Office, lead editor for the report’s Global Climate chapter, said, “2025 was exceptional when compared to the conditions in the 20th century, with temperatures well above average. When seen in conjunction with 2024 and 2023, the last three years have been truly exceptional, eclipsing records that we saw only a decade earlier.”
Global soil moisture was drier on average in 2025 than in any year since the satellite record began in 1991, driven largely by below-average soil moisture in the northern hemisphere, with particularly dry conditions above 55°N. Soil moisture affects vegetation growth, surface air temperature and extreme weather events including heatwaves and wildfires.
For the 38th consecutive year, glaciers on average lost more ice in summer than they gained in winter, continuing to thin and shorten. Since 1976, around 9,000 gigatons of water have been lost from glaciers, with 41% of that loss occurring in the last decade. At least 181 glaciers are now registered as extinct in satellite imaging records.
Last year was the warmest year on record without the influence of an El Niño event, and 2023 to 2025 were the three warmest years on record. According to all five global surface temperature datasets used in the report, January 2025 was the warmest January on record, with most other months, except December, ranking among the top three.
Carbon dioxide, methane and nitrous oxide all reached record-high atmospheric concentrations in 2025. Globally averaged CO2 reached 425.6±0.1 parts per million, a 53% increase from the pre-industrial level of approximately 278ppm. Fossil fuel emissions also hit a record high, estimated at 10.3±0.5 petagrams of carbon per year, more than three times the 3.0±0.2 petagrams of carbon per year recorded in the 1960s.
Dunn said, “The ongoing impact of rising atmospheric greenhouse gas concentrations from the burning of fossil fuels is clear. Across many metrics in this report, the conditions and events in 2025 are entirely consistent with continuing human-caused climate change.”
The report is the 36th in the Bulletin of the American Meteorological Society (BAMS) State of the Climate series, with contributions from more than 600 scientists across 60 countries. Its Global Climate chapter, edited by the Met Office, covers more than 40 climate metrics. Many of the metrics in the BAMS State of the Climate report also appear on the Met Office Climate Dashboard.
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